From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from unicorn.mansr.com (unicorn.mansr.com [81.2.72.234]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A2ADBA923 for ; Wed, 28 Jun 2023 18:33:37 +0000 (UTC) Received: from raven.mansr.com (raven.mansr.com [IPv6:2001:8b0:ca0d:1::3]) by unicorn.mansr.com (Postfix) with ESMTPS id 2509F15360; Wed, 28 Jun 2023 19:33:35 +0100 (BST) Received: by raven.mansr.com (Postfix, from userid 51770) id 17DD3219FD1; Wed, 28 Jun 2023 19:33:35 +0100 (BST) From: =?iso-8859-1?Q?M=E5ns_Rullg=E5rd?= To: Maxime Ripard Cc: Samuel Holland , Chen-Yu Tsai , Jernej Skrabec , linux-sunxi@lists.linux.dev, Michael Turquette , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Stephen Boyd , linux-kernel@vger.kernel.org Subject: Re: [PATCH v3 3/4] clk: sunxi-ng: Convert early providers to platform drivers References: <20211119033338.25486-1-samuel@sholland.org> <20211119033338.25486-4-samuel@sholland.org> Date: Wed, 28 Jun 2023 19:33:35 +0100 In-Reply-To: (Maxime Ripard's message of "Wed, 28 Jun 2023 13:41:30 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) Precedence: bulk X-Mailing-List: linux-sunxi@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Maxime Ripard writes: > On Wed, Jun 28, 2023 at 12:07:56PM +0100, M=E5ns Rullg=E5rd wrote: >> Maxime Ripard writes: >>=20 >> > On Mon, Jun 26, 2023 at 01:21:33PM +0100, M=E5ns Rullg=E5rd wrote: >> >> Samuel Holland writes: >> >>=20 >> >> > The PRCM CCU drivers depend on clocks provided by other CCU drivers= . For >> >> > example, the sun8i-r-ccu driver uses the "pll-periph" clock provide= d by >> >> > the SoC's main CCU. >> >> > >> >> > However, sun8i-r-ccu is an early OF clock provider, and many of the >> >> > main CCUs (e.g. sun50i-a64-ccu) use platform drivers. This means th= at >> >> > the consumer clocks will be orphaned until the supplier driver is b= ound. >> >> > This can be avoided by converting the remaining CCUs to use platform >> >> > drivers. Then fw_devlink will ensure the drivers are bound in the >> >> > optimal order. >> >> > >> >> > The sun5i CCU is the only one which actually needs to be an early c= lock >> >> > provider, because it provides the clock for the system timer. That = one >> >> > is left alone. >> >> > >> >> > Signed-off-by: Samuel Holland >> >> > --- >> >> > >> >> > (no changes since v1) >> >> > >> >> > drivers/clk/sunxi-ng/Kconfig | 20 ++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun4i-a10.c | 58 +++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-sun50i-h6-r.c | 56 ++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-sun50i-h616.c | 33 ++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun6i-a31.c | 40 +++++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-a23.c | 35 +++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-a33.c | 40 +++++++++++---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-h3.c | 62 ++++++++++++++------= -- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-r.c | 65 ++++++++++++++------= ---- >> >> > drivers/clk/sunxi-ng/ccu-sun8i-v3s.c | 57 +++++++++++++-------- >> >> > drivers/clk/sunxi-ng/ccu-suniv-f1c100s.c | 38 ++++++++++---- >> >> > 11 files changed, 332 insertions(+), 172 deletions(-) >> >>=20 >> >> This broke the hstimer clocksource on A20 since it requires a clock >> >> provided by the sun4i ccu driver. >> > >> > The A10 is probably broken by this, but the A20 should be able to use >> > the arch timers just like all the other Cortex-A7-based SoCs. >> > >> > Do you have a dmesg log that could help debug why it's not working? >>=20 >> The A20 works as such since, as you say, it has other clocksources. >> However, the hstimer has become unusable. If anyone was using, for >> whatever reason, it won't be working for them now. >>=20 >> Before this change, the kernel log used include this line: >>=20 >> clocksource: hstimer: mask: 0xffffffff max_cycles: 0xffffffff, max_idle_= ns: 6370868154 ns >>=20 >> Now there is only a cryptic "Can't get timer clock" in its place. >>=20 >> As it is now, the hstimer driver is nothing but a waste of space. >> I figure it ought to be fixed one way or another. > > Yeah, definitely. > > IIRC, the situation is: > > - A10 has just the "regular", old, timer > - A10s/A13/GR8 has the A10 timer + hstimer > - A20 has the A13 timers + arch timers > > We also default to the hstimer only for the A10s/A13 which aren't > affected by this patch series afaics. > > We also enable the HS timer for the A31, but just like the A20 it > doesn't use it by default, so it's probably been broken there too. > > I guess one way to fix it would be to switch the HS timer driver to a > lower priority than the A10 timer, so we pick that up by default instead > for the A10s/A13, and then convert the HS timer driver to a proper > platform_device driver that will be able to get its clock. > > The downside is that the A13 will lose some precision over its default > timer, but I don't think it's a big deal. The options I see are converting the hstimer to a platform device or reverting the change to the sun4i ccu driver. I don't personally have much of an opinion on this since my systems aren't affected. The only reason I looked at it was that I noticed a new error message in the kernel logs. --=20 M=E5ns Rullg=E5rd